An arrangement in vehicles with articulated steering

Abstract

 A vehicle, consisting of two pivotably connected units, has a vehicle part (8) in which is connected via a conventional articulated steering hinge (22, 25) to an intermediate part (7). Steering means such as hydraulic cylinders are connected between said vehicle part and intermediate part (7), which is pivotably connected to a forward part (6) attached to the other vehicle part by a journelling pin mounting (9, 10). The intermediate and forward parts are furthermore kept together by gliding means (12-19) permitting given pendular movement, said movement being in a plane substantially at right-angles to the steering plane.

Description

[0001] In the state of the art, tractors are often implemented such as to consist of two vehicle parts, each including a pair of wheels mounted unturnably in relation to the respective vehicle part. Both parts are joined together by one or more linkage systems, the vehicle being steered by mutual relative turning of the parts in the horizontal plane, the result being as so-called waist-steered vehicle. There are a number of problems in respect of the coupling between the vehicle parts. There is the question of accomplishing turning in the horizontal plane, and this would be comparatively simple to orovide an answer to, but for the fact that the vehicle does not travel on even ground all the time. In uneven terrain one vehicle part tends to assume a leaning attitude in relation to the other, and to prevent severe bending stresses in the steering hinge joint, it is necessary to take measures to provide certain degrees of freedom, i.e. mutual relative turning of the vehicle parts about a substantially horizontal axis which is, of course at right-angles to the steering axis. There are a number of designs on the market, and there are also many patents relating to the solution of problems concerned with this type of steering. The US patents 3 912 300, 4 281 848, 4 290 622 and 4 296 122 are referred to in this connection. These patents relate to designs where a certain amount of free, relative fitting between the vehicle parts is permitted whereby inter alia the mounting of the hydroaulic cylinders providing the turning movements between the vehicle parts must be made pivotable, resulting in operational drawbacks and design problems. The coupling between the two vehicle parts will moreover be comolicated.

[0002] The present invention has the object, inter alia, of solving the aforementioned problems, and provides an arrangement which is relatively simple and to the purpose from the constructional aspect.

[0003] What is characterizing for the present invention will be seen from the following claims.

[0004] The invention will now be described in detail with reference to an embodiment illustrated on the accompanying drawings, where:

Figure 1, is a view from above, schematically illustrates a tractor having articulated steering.

Figure 2 is a section along the line II-II in Figure 1.

Figure 3 is a section along the line III-III in Figure 2.

Figure 4 is a section along the line IV-IV in Figure 2.

Figure 5 is a section along the line V-V in Figure 2.

[0005] The tractor illustrated in Figure 1 comorises a forward vehicle part 1 and a rear vehicle part 2. The parts are connected to each other by a joint generally denoted by 3, and steering the vehicle is accomplished by two hydraulic cylinders 4.5 mounted between both parts. Steering is controlled from the tractor driving cabin in an unillustrated, conventional manner.

[0006] As will be seen, inter alia from Figure 2, the joint comprises three main parts, the forward part 6, intermediate part 7 and rear part 8. The forward part 6 is rigidly attached to the forward vehicle part 1. The upper portion of part 6 is formed with a bearing 9 for accommodating a journalling pin 10 fastened to the intermediate part 7. The pin 10 is locked against displacement by a circlip 11 on the portion of the pin projecting out from the bearing 9. The lower portion of part 6 is provided with a means comprising a plate 12 fastened to part 6 with screws 13. Attached to the plate and at right-angles to it there is a plate or tongue 14 projecting into an arcuate slot 15 in the lower portion of the intermediate part 7. A box-like structure 16 is built up around the slot 15, and encloses two gliding bodies 17,18 coacting with the ton- .gue 14 via a pin 19. The members 12-19 thus form a combined connection and retention means. With the aid of the illustrated arrangement, the intermediate part 7 may thus pivot about the pin 10 with the gliding bodies 17,18 gliding against the inner walls of the box structure 16. The pivoting movement is thus limited by the ends of the slot 15 or the separate stops (not shown) or the gliding bodies 17,18 coming against the end walls of the structure 16. The structure 16 has two fins 20 and 21 carrying a journalling pin 22, constituting a portion of the hin- gin^g shaft associated with the steering apparatus. A tongue 23 is disposed between both fins 20,21 and is also passed through by the pin 22. The tongue is attached to the lower portion of the part 8. This part is rigidly attached to the vehicle part 2, similar to the rigid attachment of part 6 to the vehicle part 1. The upper portion of part 8 carries a further outstanding plate or tongue 24, accommodating a further pin 25 having the same axis as pin 22 and fastened in two plates 26,27 which are in turn rigidly attached to the intermediate part 7 in the.vicinity of journal ling pin 10. At either outer side, the intermediate part 7 is provided with a lug 28,29 constituting attachment for the respective piston rod end 4',5' of the hydraulic cylinders 4,5. To one side, the part 6 has a pivot pin 30 for mounting a hydraulic cylinder 31, the piston rod 32 thereof being pivotably mounted on a pin 33 at an edge portion of the intermediate part 7. This hydraulic cylinder is provided for damping the oscillating movements between part 6 and parts 7 and 8 together. All the parts 6,7 and 8 have central cutouts 34,35 and 36, respectively. These cutouts are substantially in mutual register, and are intended for the passage of such as hydraulic lines cardan shafts going between the vehicle parts 1 and 2.

[0007] The arrangement functions such that in steering the vehicle by operating the hydraulic cylinders 4 and 5, both vehicle parts will turn about the geometric axis of the hinge formed inter alia by the pins 22 and 25. However, when the ground is uneven, one vehicle part wil.1 tend to lean in relation to the other, and there will be an os- cillatina movement between parts 6 and 7, i.e. the pin 10 will turn in the bearing 9. This means that there will be relative movement between the gliding bodies 17.18 and the box structure 16, although both parts 6 and 7 will of course be kept together by the retention means 12,14,19. Violent oscillations that may occur will be absorbed by the hydraulic cylinder 31. In practice, however, two symmetrically placed cylinders should be used. It should be noted here that irrespective of the amount of swing occurring within given limits between the vehicle parts, the hydraulic cylinders 4,5 and their piston rod portions 4',5' will never alter their positions in the horizontal plane, since part 7 cannot turn in relation to part 8. other than about the hinging axis of pins 22,25. There is no out-of-line action at all between the vehicle Darts during steering, and cylinders 4,5 will.remain in their given plane of operation. Separating the two vehicle parts is also extremely simple. The pin 19 is taken from engagement with the projecting tongue 14, via an unillustrated opening in the box structure 16, after which the circlip 11 is removed, and then the joint 33 to the hydraulic cylinder 31. Both vehicle parts may then be moved away from each other. This simple uncoupling and corresponding coupling procedure results in large practical advantages in conjunction with inspection or exchange of parts.

[0008] A plurality of embodiments may naturally be envisaged within the scope of the invention. What is essential is that the parts forming the steering hinge itself, i.e. parts 7 and 8 in the illustrated case, (constructionally constitute a unit), are coacting pair forming a constructional unit in relation to the joint means associated with said first vehicle part. The steering means 4,5 may thus be disposed between the appropriate parts without the need of considering angular attitudes caused by pendular movements between the vehicle parts.

Claims

1. An arrangement in vehicles consisting of two vehicle parts pivotably connected to each other via a joint means, characterized in that the connection between the steering hinge (20-27) itself and one vehicle part (1) is an intermediate part (7) swingably attached relative said vehicle part, and adapted for being swung in a plane substantially at right-angles to the pivoting plane of the steering hinge, the intermediate part being suspended pivotable relative said first vehicle part (1) by a journalling pin mounting (9,10), there being a gliding body (12-18), fixedly arranged relative the first vehicle part, and adapted as a stop for the intermediate part against said first vehicle part.

2. An arrangement as claimed in claim 1, characterized in that the journalling pin (10) of the intermediate part (7) is journal led in a bearing (9) arranged on a plate-like part (6) rigidly mounted on said first vehicle part (1), the opposite portion of the part (6) including a means (12,14) for releasable coacting with gliding bodies (17,18) adapted for gliding in a box-like structure (16) on said intermediate part (7), there being a fin (14) of said means projecting in through an arcuate slot (15) in said intermediate part for allowing oscillating movements.

3. An arrangement as claimed in either of the preceding claims, characterized in that the box-like structure (16) constitutes an attachment for a part of the steering hinge (20-23) itself, while the other part of the steering hinge (24-27) is attached substantially adjacent said journal ling pin (10).

4. An arrangement as claimed in any of the preceding claims, characterized in that said intermediate part is provided with mounting means (28,29) for steering means (4,5,4',5'), e.g. consisting of hydraulic cylinders, attached to said second vehicle part.

5. Arrangement as claimed in any of the preceding claims, charcterized in that said forward plate-like part (6) attached to the forward vehicle part (1) carries an oscillation damping means (30-32), also connected to said intermediate part (7) via a joint (33).

6. Arrangement as claimed in any of the preceding claims, characterized in that the arrangement has its appropriate parts made with central cutouts (34,35,36) to form a through opening for such as hydraulic lines or the like.

Drawing